Featured Review: ASUS ZenPad 8.0 (Z380C)

ASUS have been making Android tablets for a number of years, including the successful range of Transformer tablets, both Nexus 7 devices and more recently, a range of new ZenPad devices. ASUS have also sold a number of smartphones over the years too.What we are looking at today is the new ZenPad 8.0 Z380C model, which is on paper looks very much the classic budget mid / lower model in the new ZenPad range. Until recently, ASUS have used an Intel Atom processor in all of their devices and as such, it's no surprise that the ZenPad 8.0 comes with an Intel Atom processor. Going by the name, again no surprises when we see that it comes with an 8.0-inch screen. The device will, as tested, carry a £120 price tag plus the optional rear back, but at the time of writing it's not clear how much this will cost.

Specification

As I've alluded, the ZenPad 8.0 Z380C has something of a classic budget Android tablet specification on the box. When we look under the skin, there are some surprises: let's take a look:

ASUS boast that their ZenPad 8.0 has over 75% of the front devoted to the 8.0-inch display and as one would expect, the tablet is built very much around the screen. Holding the tablet in portrait mode, there are the lock and volume buttons along the right hand edge of the device. There's the headphone and MicroUSB charger port at the top of the device but it's otherwise featureless around the edge. The rear cover comes off to reveal the MicroSD card slot and the electronic connector for the rear mounted smart cases. There's a single speaker grill at the top of the device when held in portrait mode and the device does not come with a notification LED.

The ASUS ZenPad feels great in the hand with the exception of the rear back, which if not pressed back into place can creak until it's firmly put back into the spot. Even when this is the case, it has a tiny amount of movement. Otherwise, the tablet feels solid, secure and well made although the rear back is made from a hard fake leather-effect material, which although not to my taste, keeps the tablet grippy. Having the MicroUSB port at the top of the device works well enough if you want to use the device whilst recharging. There's a metallic frame around the tablet, too, which is reassuringly strong.

As far as size goes, the ZenPad is small for an 8.0-inch tablet, but thick and heavy compared with many similar, modern devices. It's shorter, narrower but thicker than the Sony Xperia Z3 Tablet Compact in terms of size but quite a bit heavier at 350g. It's smaller, thinner and lighter than the NVIDIA Shield tablet, but the ZenPad is quite a different animal to the NVIDIA powerhouse and lacks the NVIDIA's large capacity battery and heat shield.

One of the reasons why the ZenPad 8.0 is a little thicker than many competitor devices is because of the expansion slot on the back and replaceable covers. ASUS has already revealed the Audio Cover, described as "an entertainment accessory that brings cinematic, 5.1-channel surround sound to ASUS ZenPad 8.0." The Audio Cover includes six speakers (including a subwoofer), a six hour battery life and six times the volume of the standard front facing speaker. ASUS have also released the Power Case, which aims to double battery life. There may be other modules coming at some point in the future; unfortunately neither the Audio Case nor the Power Case units were available at the time of review.

Display

ASUS have given the ZenPad 8.0 a 8.0-inch, slightly above 720p resolution IPS LCD panel complete with a number of their proprietary display technologies, including VisualMaster and TruVid, which are designed to improve how the display works. According to ASUS' website, these technologies work in order to boost contrast and dynamic ranges, the same way a modern HD TV works. The technology around Tru2Life is designed to enhance and sharpen objects in the foreground and dull objects in the background and overall it works well. As with some modern televisions, sometimes it can feel that the device is applying too much image processing as objects in the front are too in-focus compared with background objects.

The ZenPad has a brightness sensor and Tru2Life also adjusts the display color temperature and brightness when under different lighting conditions in order to improve visibility. In use, you can see how the device adjusts the screen when a dialogue menu pops up on the screen, for example. For certain duties, the device dims the screen, which should help battery life. At other times, it brightens the screen to make things easier to read. There's also a toggle for the blue light filter, which ASUS claims helps reduce fatigue when using the device for longer periods of time. This changes the colour of the screen as we've seen it with other tablets, such as the Lenovo Yoga 2, removing the blue color and yellowing the tint.

Despite what the product literature claims, how does the ASUS ZenPad 8.0's display stack up in the real world? And the answer to this is: somewhere from "as expected" to "very well" depending on what you are doing with the device. The tablet's resolution isn't FHD (1080p) or QHD (1440p), but resolution is only part of the equation as to what makes a good display - color reproduction and consistency of touch response are in there too. Another factor, and one that it's easy to take for granted, is how resistant the front glass is to fingerprints. Piecing these parts of the equation together, the ASUS is resistant to smudges, is responsive and has respectably bright colors. The resolution ticks the "good enough" button.

For the user interface and standard reasonably static applications, the ZenPad's screen is "as expected." However, when you come to watch video or other moving images, ASUS' display technologies come into their own. Here, moving video image quality is much better than expected and the screen offers a good range of brightness and viewing angles, although it is still a little bit too bright for a dark room. The display avoids the subdued colors that we sometimes see with less expensive panels. It's also very usable thanks to the oleophobic coating to keep smudges at bay and the low reflectivity of the front glass. If you're planning to watch plenty of media with your tablet, ASUS' screen technologies work beautifully.

Sound

ASUS have given the ZenPad 8.0 a single front facing speaker, which sits at the top of the device as you hold it in portrait mode. It's great to see a front facing speaker and it makes a difference to anything we might do on the device that uses audio. It's not the most loud of speaker systems and I have heard it resonate, but for movies, music and games, the speaker works very well. ASUS provide the user with Dolby-enhanced sound so you can put the device into gaming, movie or music mode, or stick with automatic. Having speakers are much better on the front of a device compared with the rear!

The device comes into its own when listening to music or movies using the earphones, where ASUS' integration of DTS HD Premium Sound gives the sound a genuine richness. In short, the ZenPad sounds great over earphones.

Performance, Memory, Multitasking

The Performance, Memory and Multitasking section of this review is going to be a little long, because it's here where things get a little complicated and we run into the ASUS ZenPad's first compromise. The tablet is based around the Intel Atom X3-C3230RK System-on-Chip, which according to the marketing material is a quad core, 64-bit processor. This is true, but the maximum clock speed is not detailed - more on this later. Unfortunately, the ASUS runs Android Lollipop in 32-bit mode; the processor is unable to stretch those 64-bit legs. Now, the number of bits that a processor has is largely academic when it comes to device performance. It will allow for a device to have greater memory attached, but for a 1 GB tablet, this is academic.

This is the SoFIA processor, designed for emerging markets and entry level tablets and is designed and built by Rockchip on a 28nm process (which is why the product number has "RK" in it). The SoFIA is designed for emerging markets and for this is needs to be inexpensive. Performance takes a back seat: the processor has a low clock speed of 900 MHz. It's also built on the older, tried and tested 28nm process. It uses an ARM Mali GPU rather than Intel's HD GPU, again to keep costs down.

The X3 is also the first modern device I've used with a sub-1.0 GHz processor in a long time, even if it does have four application processor cores. Neither the clock speed nor the number of application cores is a true measure of a processor's performance as many applications only use one or two cores and different designs use different architecture. I had high hopes for the Atom X3 given my recent experience with Intel Atom processors in Android devices. Intel, Rockchip and ASUS are hoping that the Atom X3 is "good enough" when it comes to performance.

The Atom is supported by 1 GB of RAM and the ARM Mali 450 MP4 GPU, which further underpins the lower to mid-range status of the device. As is commonplace with other 1 GB tablets, one of the ASUS' problems is that it runs low on memory when switching between applications. This can cause the device to pause for anything from a moment (showing by decelerating animations) to a few seconds as it clears out old data and saves this to internal storage. The tablet can feel sluggish and for somebody used to an Android tablet, it is intolerable. However, mid way through my review time with the device and this significantly improved matters. After the update, it behaves like other 1 GB tablets: switching between applications causes the operating system to take a pause and moving between Google Docs and the Chrome browser often causes each respective application to reload the document or web page in use, but this is a common problem with these two heavyweight applications. There are lags throughout the operating system when switching between applications or returning to the launcher and unfortunately the ZenPad suffers from this behaviour worse that everything else I have recently used. As with many similar inexpensive Android devices, performance noticeably deteriorates with several connected applications installed such as social media services.

In order to gauge the performance of the tablet, I tried a number of applications including social networks, Google Docs, the Chrome browser, YouTube and a variety of simple games. In each case the ZenPad was sluggish when moving to a new application. Once in a given application, the device performed acceptably, but depending on the application in question it could take several seconds for it to be ready. I wasn't able to scientifically test how long it would take to open individual applications, other than typically about twice as long as it does to open the same applications as the two other tablets to hand, the 2013 Google Nexus 7 or 2014 Lenovo YOGA 2 Tablet. However, once in an application, the device performed just fine. I did notice that during demanding tasks, I noticed that the top rear of the device would warm up, which is presumably where the System-on-Chip lives. The ZenPad never felt uncomfortably hot even after an extended period of use.

I ran the PCMark benchmark on the device and it initially scored 2,245, but during my testing the device received a software update and this helped the performance issues I was experiencing. The PCMark score was bumped up to 2,310, but the change in device behaviour was much better. All the same, 2,300 points is disappointing in the context of a modern tablet. The Vodafone Tab prime 6 scored 3,285, which is based around a quad core, 1.2 GHz Qualcomm Snapdragon 410, and the venerable ASUS-made Nexus 7 (2013) shows 2,932, which is based around an older generation, 1.5 GHz, 32-bit, quad core Snapdragon 600 (or S4 Pro).

The Atom X3 is unfortunately underwhelming in the ASUS ZenPad. I suspect that this behaviour is because the operating system is running low on memory and the Atom X3 is unable to clear free space quickly. Perhaps Intel and Rockchip have given the system-on-chip a particularly sluggish RAM controller or perhaps ASUS' tweaks to Android have hurt performance? Either way, it's something that could potentially be solved with more memory, as perhaps this will lighten the load on the 900 MHz processor.

WiFi, Bluetooth

The ASUS ZenPad 8.0 comes with single band (2.4 GHz) WiFi and Bluetooth 4.0. I'll write about the Bluetooth radio first, which performed as a modern device equipped with Bluetooth 4.0 should: it makes no obvious difference to the battery life when active and was able to connect to a number of different devices at the same time. I was able to connect the ASUS to a Bluetooth wireless keyboard whilst using my smartphone's Internet connect via Bluetooth.

For the WiFi, I found the ASUS to be less than the usual perfectly reliable than I have come to expect of my Android devices. There were occasions when the device would stop connecting with the Internet even though it still had a valid connection with my router. Cycling the WiFi off and on was enough to correct the issue. It happened every two or three days and there was no obvious pattern. I've had other Intel Atom devices do something similar with a number of WiFi routers over the last couple of months and I'm not sure what the issue is. There's no support for 5 GHz WiFi or any mobile data connection, nor have ASUS given the ZenPad an infrared port or NFC - this is standard fare for a lower priced tablet.

Camera

The ASUS ZenPad 8.0 comes with the near-standard 5MP rear mounted, 2MP front facing camera set up. ASUS state that the cameras both use PixelMaster technology. The rear mounted 5MP unit has an aperture of f/2.0 and features HDR. Both cameras include real time beautification technology, too. The front facing camera is a 2MP unit with an aperture of f/2.2 and a 75-degree field of view, boosted by ASUS' 140-degree panoramic selfie capture more.

Nevertheless, cameras and tablets do not tend to go well together: the device is a bit too big to be easily handled to take pictures, yet manufacturers continue to mount cameras on the rear of a tablet. I've included a selection of pictures here for the interested.

Battery

The ZenPad 8.0 comes with a 15.1 watt hour battery, which at 3.7 volts, equates to a little short of 4,100 mAh. This is slightly low for an 8.0-inch tablet. Nevertheless, the device has a low screen resolution and a low powered Intel Atom processor, plus minimal radios to suck power. On the original software version the ASUS came with, battery life was poor and I would see somewhere from three to four hours of screen on time before the device needed a recharge. However, the device was updated received half way through the review process and this almost doubled battery life. Over a varied workload including writing via a wireless keyboard, benchmarking, gaming, watching music videos via YouTube and using the Google applications, the device was looking at showing around five hours of screen on time. Whilst this isn't brilliant, this was a demanding workload. Under better conditions, the device was showing it could stretch to close to ten hours of screen on time. It makes a big difference to how usable the Zenpad is for me.

For the power users amongst us, ASUS have given the device some neat software tricks designed to maximize battery life, including the Auto-Start Manager, which prevents applications from starting along with the operating system. ASUS have also given the device their own Power management screen, with three Power Saver modes: Ultra-saving mode, Optimized mode and Customized mode. Ultra-saving mode is similar to stock Lollipop's battery saving mode by reducing the clock speed of the processor and limiting background data. Optimized mode dims the screen but is designed to blend performance with battery life. The Customized mode allows the user to pick how the device works, with optional push notification service enabling and a changeable brightness setting. In my time with the ZenPad, I adjusted these features, which in many respects appear to prevent Android from doing what Android does very well (this being to multitask). However, as a means of preventing applications from launching when the device reboots so as to improve performance, this is something to consider.

ASUS sell the Power Case, with an additional 16 watt hour battery for the promise of extended battery life. This optional extra shows up on the ASUS' screen detailing the amount of charge left. For those customers who expect to be away from a power socket for a long time, the Power Case could be a completely brilliant accessory - under those optimum conditions, perhaps the ASUS could see twenty hours of screen on time.

Software

The ASUS ZenPad runs ASUS' ZenUI. This is a reasonably heavy skin sitting over Android 5.0.2 Lollipop. There are some elements of Material Design included, such as the task switcher, and the launcher looks close to the old stock launcher (rather than the newer Google Experience Launcher). It has many additional features over the stock Google launcher, including the ability to change the sort order, lock applications (prevent them from being accessed without the PIN code), hide applications and change the application grid size. The launcher shows the number of notifications waiting for your applications, too, which is a nice trick. Overall, the launcher adds quite a bit to the device and makes it easy for the power users to set up things as to how you want it.

ASUS have included a large number of their own applications with the device, but have also made it easy to remove or disable these via a Uninstall / Disable option in the launcher. The ZenUI also comes with its own set of weather clock widgets, which look good on the home screens. Dive into the Settings application and you'll see a reasonably standard set of options but some extras, including ASUS Cover (settings to enable or disable optional smart covers and the automatic unlock function) and ZenMotion, whereby you can lock or unlock the device using a double tap and launch applications via swiping across the lock screen.

Another subtle tweak with the device is how when unlocked it using a PIN, you don't need to tap "Enter" but instead, once you have the right PIN it will automatically unlock for you. That's a nice touch that I really appreciate - and miss when I go back to a stock device!

ASUS include a large number of bundled applications on the device, including many of their in-house cloud services together with third party applications. Most of these are easy to remove (that the launcher has the ability to easily remove or disable applications is handy here). Many of the more experienced Android users will likely take several minutes removing the surplus applications from the device!

Conclusion

The ASUS ZenPad 8.0 has been an interesting device to test, because it is a device of stark contrasts and compromises. To handle, it generally feels great - the little movement in the rear changeable cases apart. It's solid if a little heavy. The screen is great for videos and the speaker works great, especially with headphones in.

It is, however, powered by a quad core, 900 MHz processor with 1 GB of RAM. It has moments of slowness, such as switching between a large, image-heavy document to a complex webpage: things can grind to a crawl with half a dozen connected social network applications on the device. For lightweight tablet duties, the ZenPad works great, but ASUS could massively improve the device with a more powerful processor and, especially, 2 GB of RAM.

I grew up with 8-bit computers and moved into PDAs in my professional life, using a number of devices from early Windows CE clamshells and later. Today, my main devices are a Nexus 5X, a Sony Xperia Z Tablet and a coffee cup.